As widely known, a wireless pay television system provides individual subscribers with television programs paid for and limited by individual agreements. Some prior art systems have some kind of receiving system, each provided with a hard-wired decoder permitting reception of only one of a plurality of program categories, so that the receiving system can receive a television program only when a category-defining signal supplied from the broadcasting station conforms with the assigned program category.
However, such a prior art system has the drawback that when a subscriber amends his subscription category to another, it is necessary to replace the entire receiving decoder with another, and further that a subscriber can disassemble his receiving system and easily rearrange the category-defining hard-wired circuit so as to receive other program categories to which he is not entitled.